Parasiticidal composition



R. CROSS PARASITICIDAL COMPOSITION V June 29,19

Filed March 22, 1939 w s/fl a. 6 NW 60 V 0 6 0 /w/ flaw EM mm MM NW Y B /8 m ATTORNEY.

Patented June 29, 1948 City Testing Laboratory, Kansas corporation of Missouri 7 Application March 22, 1939, SerlaiNo. 264,708

This invention relates to the composition and manufacture of insecticides and fungicides, these two terms being included in the word "parasiticide." It more particularly refers to the type of parasiticide in which clay is incorporated as a filler, emulsifying agent or a suspending agent.

In the present art there are four general types of parasiticides, namely, (1) liquid compounds,

(2) emulsions, (3) suspensions and suspendable, This inmaterials, and (4) dusting materials. vention is primarily concerned with the last three types.

According to present practice there is considerable difiiculty in preparing emulsions of parasiticidal agents which will be stable upon storage. Soaps are frequently used for this purpose but are not entirely satisfactory for various reasons. The preparation of suspensions of active 'parasiticidal agents also presents a number of difllculties in the present art. .Among these are the difliculty of mixing dry powders with water in a sprayer and the difilculty in supporting parasiticidal agents uniformly throughout the suspension so that when the dilute solution is sprayed a uniform coverage will result. -This difficulty is particularly bad where only a small quantity of the effective agent is being used. One of the most serious troubles presented in the present art is with mixtures using lime as a dispersing or carrying agent for the active parasiticide. Lime-sulfur sprays release lime in situ on the foliage being treated and cause serious burning effects. Furthermore, the lime-sulfur mixture reacts with the carbon-dioxide in the air to liberate hydrogen is the diillculty of obtaining a suitable intimate mixture of clay and sulfur where this type of material isused bearing in mind the fact that the sulfur must be in very fine form to become available for its appointed use.

Bentonite is one of the clays which has been suggested for use with sulfur but it has some disadvantages as compared with the materials which are hereinafter employed in accordance with thepresent invention. For example, a mixture of bentonite dispersed with molten sulfur is City, Mo., a

4 Claims. (01. 167-14) 2 relatively difilcult to grind. Furthermore, bentonite has a relatively high specific gravity of ill around '10 lbs. per cu. ft. Where the parasiticidal agent is a salt bentonite is ordinarily unsuitable for mixing therewith because it is well known that bentonite will not properly disperse to a colloidal form in the presence of salts or electrolytes. One of the objects of the present invention is to overcome these difficulties existing in the present art and to provide new and improved compositions containing parasiticidal agents andnew and improved means for producing such compositions. Other. objects will appear hereinafter.

The invention consists primarily of two parts, the first of which is to furnish a'new material as a dispersing agent and filler for parasiticides, and

the second is to provide a new method of making a mixture of a dispersing agent and a parasiticidal agent. both when mixing various agents to obtain a water'suspension and to'intimately combine sulfur with a sticking type of carrier.

The new material which I have discovered to be a great improvement over the present artfor the production of parasiticides is a Floridaa Georgia type fullers earth which is found in Y northern Florida and southern Georgia in the general districts of Quincy, Florida and Attapulgus, Georgia, and in a large area in northeentral Florida near Ocala. A lump of this clay-when added to water will not form a gel and willinot swell as in the case of bentonite. Suchaclay will not react with magnesium oxide as does bentonite. Its specific gravity is about 34 lbs. to 35 lbs. per cu. ft., as compared with a specific gravity of about 70 lbs. per cu. ft. for bentonite. This type of clay, furthermore, has base exchange properties and may be generally characterized as a natural zeolitic clay. When passed through a colloid mill either with or without undergoing base exchange activity it will produce a viscous mixture with from 1% to 10% concentration in water. For example,-a 4% mixture when run through a colloid mill will produce a suspension which has a viscosity of from 20 to 100 centipoises, as determined by the Stormer viscosimeter. One sample of this clay, for instance, when 4 parts thereof were mixed with 96 parts of water, gave a viscosity of 48 in a colloid dispersion mill. The

same mixture when shaken in a shaking machine or an ordinary bottle gave a viscosity of 3, and when mixed with a blade stirrer such as a malted milk machine, gave a viscosity of 19. Generally speaking, about 1% to 5% of the clay will give a viscosity within the range of 5 to 50 centipoises when mixed with water.

' ence of salt solutions. As an illustration, separate mixtures of bentonite and thebase exchange clay-herein referred to were-made by adding to the re p tive clays a 43% solution of sodium thiosulfate. 'Each mixture consisted of 8.75

grams of clay in 100 cc. ofwater solution. The

viscosity of the bentonite mixture was zero while that of the Florida-Georgia fullers earth mixture was 16.5 centipoises, Stormer. The bentonite mixture started settling immediately and settled l 36% in two hours, whereas the other mixture remained as a suspension during the 24 hours of the test. This ability of the base'exchangetype of clay to disperse in salt type solutions makes available the combination of parasiticidal salt solutions with a sticking agent which insures the retention of the soluble salt on the foliage. Examples of these solutions are copper sulfate, copper chloride, zinc sulfate, sodium chloride, sodium sulfides, sodium thiosulfate, calcium sulfides, etc. It is obvious that without the application of the solution to foliage as a dispersion of the base exchange clay the solution would .be washed off with the first rain. It is sometimes desirableto control the pH of the spraying solution and this is easily done with our base exchange clay without harming the suspension, since it has the ability to disperse in various types of media .over a wide pH range. this range being approximately from pH 3 to pH 13. The material has no causticity and, therefore. is a great improvement over the lime type of material now used. Moreover, there is no loss of sulfur due to chemical action when sulfur is combined with thistype of clay.

Since the material may be mixed in water having an appreciable salt content, there is no decrease in gel value when the material is dispersed in mineralized water so often found in the field. Another advantage of this type of clay resides in the fact that it may be stimulated as to gel value by the addition of any of a number of stimulating agents either added to the dry powder before dispersing, or after dispersing in water. Some of these stimulating agents are calcium hydroxide, magnesium oxide and sodium hydroxide. The gel formed by dispersion of a base exchange clay of the type herein described makes an excellent suspending means for insoluble parasiticides. mixed with the base exchange clay before dispersing or may be stirred into the gel after dispersion. Typical examples of such insoluble parasiticides are lead arsenate, copper arsenite, sulfur, etc. v

Parasiticidal compositions made with this base exchange clay have great advantages when used as a medium for dusting. Since this clay weighs only 36 lbs. per cu. ft., it gives nearly 2 times the filler characteristic of bentonite and yet it retains the advantage of sticking to the foliage treated. Furthermore, parasiticidal mixtures of this clay with insoluble materials such, for. example, as sulfur, give much softer grinding mixtures than The parasiticidal agent may be 4 are obtained with other clays, such as bentonite.

Other features and advantages-of the invention will appear from the following description and the accompanying drawings, in which:

Figure 1 represents diagrammatically one form of apparatus which may be used in accordance with this invention for preparing parasiticidal materials;

Figure 2 represents a modified form of apparatus;

Figure 3 represents another form of apparatus which may be used in practicing the present invention;

. Figure i illustrates another form of apparatus, which may be used in accordance with this invention.

Referring to Figure 1, the apparatus described is designed primarily for preparing a parasiticidal composition of clay as herein described and sulfur. The aparatus shown comprises a sulfur bin l8, a clay bin l2, a melting tank H for melting the sulfur and comprising a heating coil Ill, an agitator i8, a water line 20 provided with a valve 22 and-an outlet line 24. Outlet line 24 is provided with a valve 26 and is connected through by-pass lines or conduits 28 and 30 to a pump 32. Line 28 is controlled by valve 34 and line 30 by a valve 3.6.

Line 24 connects to the inlet side of a dispersion mill 38 which may be of the type shown in U. 8.

'Patent 2,044,757. Dispersion mill 3B is provided with a conduit 40 through which steam may he introduced and which is controlled by valve 4 2. Connected to mill 38 is a water line 44 through .which water may be pumped by pump 46 to mill 38. The contents of mill 3! may be discharged through outlet pipe 48 and spray nozzle 50 to a chamber 52 provided with a fan 54 and emptying through an outlet 56 to a separating chamber 58 where fine material and coarse material may be separated by'a screen 80, the fine material passing to compartment 64 and the coarse material remaining in compartment 82. If desired, the coarse material in compartment 62 may be returned to vessel M by any suitable means. Compartments 62 and 6| are provided with outlets 66 and 88, respectively.

According to this method of operation, sulfur may be introduced into the system from storage vessel Ill and the base exchange zeolitic clay' from storage vessel l2. The two ingredients arebrought together in the proper proportions in IS in said tank being sufflciently high to melt the sulfur and preferably within the range of about to about 0. Water is introduced through conduit 20 controlled by valve 22 and super-atmospheric pressure is maintained in vessel ll, the pressure required being approximately 45 lbs. per sq. in. or higher. Under these elevated temperatures and pressures the molten sulfur and the clay are mixed with the water by means of a suitable agitator l8. Thereafter the mixture is passed through conduit 24 controlled by valve 26 to dispersion mill 38 which likewise may be maintained under elevated temperatures and pressures suihcient to keep the sulfur in its molten state and to prevent boiling of the water. Instead of flowing the mixture by gravity into dispersion mill 38 it may be desirable, particularly where the mixtureis heavy or viscous, to close valve 26 and open valves 34 and 38, thereby permitting the mixture to be pumped by means of pump 32 into dispersion mill 38.

The desired temperature in mill 38 may be by pumping through conduit 44 with pump 46.

After the clay and sulfur have been thoroughly dispersed in the water or .other liquid medium the dispersion is passed through an outlet 48 at the exhaust end of the mill and an atomizing vent 50 through which the mixture is expanded in the form of a fine mist in tower 52. It will be recognized that a comparatively small drop in temperature solidifies the sulfur and this may be aided by a fan 54. The intimate mixture of sulfur and clay falls into the cooling receptacle in small particles. It is sometimes desirable to exhaust the mixture into a cooling and drying medium. The majority of the material obtained in this manner is fine enough to be suspended in water for spraying purposes, and thus grinding subsequent to the combination of the clay and sulfur is not necessary. If the percentage of clay is high compared to the percentage of sulfur in the mixture, more drying effect is required in the atomization stage and 'a softer particle results. However, the opposite is true and a high percentage of sulfur compared to the percentage of clay gives a harder particle. The particle in any case is softer on the other hand than the particle obtained where bentonite is used instead of the base exchange clay. Sometimes it is de sirable to screen theparticles obtained and re- I circulate particles above a predetermined size for subsequent reprocessing. This may be accomplished by passing the clay-sulfur mixture through screen 60 in vessel 58, the fine mixture being recovered in compartment 64 and removed through outlet 68 and the coarser portion of-the mixture remaining in compartment 62 from which it can be removed through outlet 66 and returned to the system for further processing. This coarser mixture may be returned either to tank it or dispersion mill 39. Instead of returning the larger particles to the system they may be ground if desired. In some instances it may be desirable to incorporate an agent in the sulfurclay mixture which has a high vapor pressure that will give rapid drying upon exhaustion from the mill 38 through atomizing vent 50.

It will be understood that the amount of water introduced into the system through conduit 2H, conduit 44 or steam line MI is subject to variation and may be relatively small so that to outward appearances the mixture in tank I4 and in dispersion mill 3B is substantially a mixture of clay and molten sulfur. We have found, however, that for this particular clay the amount of water introduced into the system must be such as to prevent the vaporization of the natural moisture content of the clay below about 10%. The pressure in tank It and dispersion mill 38 may be developed partially by vaporization of the natural moisture in the clay, particularly where the amount of clay is relatively large, but usually it will benecessary to add water, steam or some "6 I20. Clay may be introduced into chamber I" through opening I22. Zone I24 is a cooling zone in the lower part of tower I ll. The upper part of tower H4 is connected through line or conduit I26 to a suction fan I23 which in turn is connected through conduit I30 to a condenser I32. Condenser I32 is connected through conduit I34 to pump I38 which in turnis connected to sulfur boiler IIII through conduit I38. Outlet I is provided to remove the contents of tower I ll.

According to this method the sulfur is vapor ized and while in vapor form is brought into con.- tact with-the clay and condensed thereon. This may be accomplished by vaporizing sulfur In boiler Hit and passing the vaporized sulfur through conduit II2 to a point near the bottom of a wedge tower 4 so that the sulfur vapors will rise through base exchange zeolitic clay which may be introduced through opening I22 to chamber II8 and thence through vibrating screen I20 to the top of thetower. The rate of settling of the clay through the tower determines the proper rate of sulfur flowing upwardly through the tower. In addition to this the total quantities of clay and sulfur are determining factors as-to the rate of flow of the two materials in the tower. The vapors may be exhausted continuously from the top of the tower through conduit I26 by meansof suction fan I28 and re circulated through conduit I30 to a condensing zone I32 from which the condensed material is passed through conduit I34 to a suitable pump L36 which returns it through conduit I33 to the vaporizing zone IIII. This system of circulation may be carried out continuously or semi-continuously. It is usually desirable to heat the clay in the tower to prevent too rapid condensation of the sulfur vapors, and this heat may be varied through the length of the tower, for example, by passing a heat medium through a jacket Iii. Thus the clay in the part of the tower where the sulfur vapor enters may be heated to a higher temperature than that at the far end of the unit and the temperature may be graded downwardly from the sulfur entrance to a cooling zone I24. It has been found that this is a very efficient method for intimately incorporating the sulfur into the clay. The efficiency of the mixture also depends upon the fineness of the clay being treated. One of the advantages of this method is that it eliminates the necessity for re-grinding the sulfur-clay mixture, since the mixture which is recovered through outlet I40 is ready for use.

Another modification is illustrated in Figure 3 in which sulfur boiler III! is connected through conduit2I2 to tower 2M. A pulverizer 2 is connected through a conduit or line 2I8 to a blower 220 which in turn is connected by means of a conduit or line 222 to the upper portion of tower 214.- In the upper extremity of tower 2 is connected through.a conduit 228 to a blower other convenient means for forming vapor pressure either in tank It or dispersion mill 38, or both, in order to prevent excessive dehydration of the clay. In some cases it may be desirable to add a gas in order to increase the vapor pres- 230 which in turn is connected through a conduit 232 to sulfur boiler 2"). In the lower portion of tower-2H is a cooling zone 234 and at the lower extremity is an outlet 236. The operation of this system'is similar to the operation of the system just described except that the clay is pulverized in a pulverizer v2I8 then passed through conduit 2| 8 and blown through conduit 222 to the upper portion of tower 2, which it enters through opening 238. Thereafter the pulverized clay mingles with sulfur vapors introduced into tower .2 from sulfur boiler 2I0 through conduit 2I2.

Any sulfur vapors escaping through the top of i amuse by condensing them in condenser 22' and passing them through conduit 22 to blower I, which returns them through conduit 282 to sulfur boilerfli.

In Figure 4 the apparatus illustrated comprises.

a rotating kiln mixer ill provided with a sulfur vapor outlet line 3|! connected to a condenser 3, which in turn connects through conduit lit to a pump 3". From pump III aconduit I20 connects to a sulfur boiler 322. Another conduit "4 leads from sulfur boiler 322 to rotary kiln mixer 3l0. In this system the sulfur is vaporized in boiler 322, passed through conduit I24 to rotary kiln mixer Oil and there mixed with clay introduced through hopper "I. Rotary kiln 820 is provided with baflles of any suitable type and in this manner the clay and the sulfur can be thoroughly mixed, the mixture being discharged through asultable outlet to a receptacle I28 and any unmixed sulfur vapors being returned through conduit M2, condenser Ill, conduit lit. pump M8 and conduit 320 to sulfur boiler 322. The same factors of how of sulfur vapors and clay apply as with the wedge tower Ill in Figure 2. This type of arrangement is excellent for maintaining a gradual temperature drop from the inlet end of the kiln downwardly toward the outlet end.

It will be understood that in the procedures described with reference to Figures 2, 3 and 4 water may always be introduced into the system at any;,convenient point in order to prevent dehydration of the clay below 10% water. It will be appreciated that these systems may also be used in making parasiticidal materials from other types of clays or. filler materials.

Generally speaking the practice in using this new type of clay which we have discovered conforms to the present use of such materials insofar as the proportions are concerned. Where the clay is to be used as a suspending agent in the form of a water dispersion the addition of 5% of clay on the weight of the water to be used gives excellent results. A typical formula for the use of this material is as follows:

Lead arsenate pounds 3 to 5 Base exchange zeolitic clay ..-do 40 Water gallons 100 The mixture may be placed in a sprayer tank accompanied by agitation to secure dispersion.

.The clay does not hydrate so rapidly that clotting or lumping occurs. Another convenient way to mix the solid material with'water is to connect the outlet of a hopper type vat mixer to the outlet of the pump and allow the outlet of the vat mixer to empty into the tank. The water from the tank is pumped through the mixer and the clay added to the stream in the hopper. When the desired amount of clay has been added a few cycles through the vat mixer and pump will make a good dispersion.. The pump outlet is then connected to the spray nozzle.

A typical sulfur spray mix is:

. 8 cosity is to be maintained, the following is a typical formula:

Hydrated" lime DOImdBa; 0.5 Sulfur do Base exchange zeolitic clay do 20.0 Water g llons 100.0

. tions in contact with the foliage a small amount of starch, dextrine or casein material may be added.

If it is desired to make a concentrated dispersion for shipment in the liquid form the base exchange clay may be used with water in the ratio of 1 part base exchange clay to 4 parts of water, plus the parasiticide which is to be incorporated therein. In making this type of mixture complete hydration of the clay is of great importance and this is best accomplished by violent agitation. Such a mixture can be added to the user's sprayer tank with comparatively little stirring required.

We have found that the use ofa dispersion mill to make an intimate mixture of this base ex- Fine sulfur pounds 5 to 40 Base exchange zeolitic clay do 40 Water gallons 100 change clay and parasiticidein water is very effective. The mill shown in patent No. 2,044,757 is excellent for this purpose. In making such dispersions the clay and parasiticide may be premixed and added to the water prior to feeding into the mill, or all may be fed into the mill simultaneously. When making this type of mixture with sulfur, sublimed sulfur seems to be the best type, althoughhnely ground material will sometimes sumce. In making fresh water emulsions a mill is necessary. There are many materials which are immiscible with water but which have an excellent parasiticidal effect. Examples of such materials are chlorinated parafllns and various hydrocarbon compounds such as kerosene, gasoline and even crude oil. A typical composition which may be made from such materials in accordance with the present invention is illustrated as follows:

The mass is then run through a dispersion mill. In this type of composition the base exchange zeolitic clay has been found to be a greatly superior emulsifying agent giving a smooth creamy mixture. As already indicated it is sometimes desirable to make a combination of emulsion with a saline solution and a clay of the type herein described is excellent for this purpose.

The ease of making a suspension with a minimum amount of mixing is greatly increased by the addition of a salt to a mixture of sulfur with a clay of the type herein referred to. An example of such a mixture is as follows:

Pounds Base exchange clay 5 Sodium chlori l. Sulfur 5 Water of base exchange zeclitic clay and sulfur upon cooling is soft and easily ground, whereas the mixture with bentonite is very hard and is very ease of reaching small particle size which easily disperses with water. The, addition of a small amount of sodium chloride to the mixture before heating results in a final product which has suspension characteristics far superior to thesuspension characteristics of the mixture without the salt. Other salts of the class of sodium chloride may be used for this purpose. The addition of salts of the sodium chloride type is also of advantage 'in mixtures of fullers earth, sulfur and other agents such as lead arsenates, copper compounds, etc. Generally speaking, among the salts which may be used are the alkali metal salts including sodium chloride and potassium chloride, the soluble alkaline earth metal salts including calcium chloride and other soluble salts.

' It will be understood that many variations may be made in the nature and proportions oi materials which may be employed in making parasiticidal compositions in accordance with this invention regardless of whether these-compositions are in powder form to be applied by dusting or in the form of emulsions or suspensions to be ap-' plied by spraying.

Having thus described the invention, what I claim as newand desire to secure bygLetters Patent ofthe United States is:

1. A parasiticidal composition comprising a mixture of a Florida-Georgia type-fullers earth metals and the alkaline earth metals, said salt being in suiilcient amount to substantially facili-. tate the dispersion of the mixture in water and containing a substantial amount of its natural water of hydra ion, a water insoluble parasiticidal material, and a salt selected from the group consisting of the water soluble salts oi' the alkali improve 'the suspension characteristics 01' the dispersion thus formed, said fullers earth having dispersion characteristics such that the dispersion in water of less than about 10% but substantial quantities thereof produces a dispersion having a viscosity greater than about 5 centipoises.

2. A composition as claimed in claim 1 wherein the salt is sodium chloride.

,3. A composition as claimed in claim 1 wherein the salt is potassium chloride. 4. A composition as claimed in claim 1 wherein the salt is calcium chloride. I ROY CROSS.

REFERENCES mm The following references are of record in the file of this patent:. V

UNITED STATES PATENTS Number Name Date 100, 327 Robbins Mar. 1, 1870 1,511,623 McConnell Oct. 14, 1924 1,520,197 Meeks Dec. 23, 1924 1,532,631 Molz Apr. 7, 1926 1,550,650 'Banks Aug. 18, 1925 1,694,620 Jaeger Dec, 11, 1928 1,733,958 Gardner Oct. 29, 1929 1,793,922 Funk Feb. 24, 1931 1,870,383 Sanders Aug. 9, 1932 1,934,989 McDaniel Nov. 14, 1933 1,986,218 Remy Jan. 1, 1935 2,014,609 Barnhlll Sept, 17, 1935 2,157,861 Nikitin et al May 9, 1939 2,304,749 Cross et a1. Dec. 8, 1942 2,415,282 Hartshorne Feb. 4, 1947 

